I hear the message you all are sending. I've taken my bow and arrows into Canada without worry, and have frequently found campgrounds that were secluded enough that I could wander off into the woods and shoot a few pinecones.
However, despite the fact that from all I can discover, the rules regarding bows in Canada and Mexico are the same, I don't think la policía in Mexico always play by the rules. I don't think I could take my bow and arrows into Mexico without worrying about it, and if I’m going there on vacation, why create something to worry about? I wouldn't feel the same worry if I were going there to hunt with a Mexican guide, because I think they know how to handle those things. I read someplace that even if you speak fluent Spanish (which I do) you should let your Mexican guide handle the paperwork for you.
So instead, I just ordered a Saunders Power Pull, which will keep me in shape as well as my daily bow exercise would (I hope). I would have rather had a Bow Trainer because it would seem more like pulling a bow, but I can't store something 36” long in my luggage.
I had hoped to bring a bow I could shoot at an archery club I found on the internet in Oaxaca. I will probably go by there anyway, and maybe I can scrounge up a bow I can shoot.